//--------------------------------------------------------------------------
//	Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
//  All rights reserved.
//
//	Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are
//  met:
//
//	Redistributions of source code must retain the above copyright notice,
//  this list of conditions and the following disclaimer.
//	Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//	Neither the name of the Drew Davidson nor the names of its contributors
//  may be used to endorse or promote products derived from this software
//  without specific prior written permission.
//
//	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
//  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
//  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
//  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
//  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
//  DAMAGE.
//--------------------------------------------------------------------------
package org.more.ognl;
import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Enumeration;
/**
 * This is an abstract class with static methods that define the operations of OGNL.
 * @author Luke Blanshard (blanshlu@netscape.net)
 * @author Drew Davidson (drew@ognl.org)
 */
@SuppressWarnings({ "unchecked", "unused", "rawtypes" })
public abstract class OgnlOps implements NumericTypes {
    /**
     * Compares two objects for equality, even if it has to convert
     * one of them to the other type.  If both objects are numeric
     * they are converted to the widest type and compared.  If
     * one is non-numeric and one is numeric the non-numeric is
     * converted to double and compared to the double numeric
     * value.  If both are non-numeric and Comparable and the
     * types are compatible (i.e. v1 is of the same or superclass
     * of v2's type) they are compared with Comparable.compareTo().
     * If both values are non-numeric and not Comparable or of
     * incompatible classes this will throw and IllegalArgumentException.
     *
     * @param v1    First value to compare
     * @param v2    second value to compare
     *
     * @return integer describing the comparison between the two objects.
     *          A negative number indicates that v1 < v2.  Positive indicates
     *          that v1 > v2.  Zero indicates v1 == v2.
     *
     * @throws IllegalArgumentException if the objects are both non-numeric
     *              yet of incompatible types or do not implement Comparable.
     */
    public static int compareWithConversion(Object v1, Object v2) {
        int result;
        if (v1 == v2) {
            result = 0;
        } else {
            int t1 = getNumericType(v1), t2 = getNumericType(v2), type = getNumericType(t1, t2, true);
            switch (type) {
            case BIGINT:
                result = bigIntValue(v1).compareTo(bigIntValue(v2));
                break;
            case BIGDEC:
                result = bigDecValue(v1).compareTo(bigDecValue(v2));
                break;
            case NONNUMERIC:
                if ((t1 == NONNUMERIC) && (t2 == NONNUMERIC)) {
                    if ((v1 instanceof Comparable) && v1.getClass().isAssignableFrom(v2.getClass())) {
                        result = ((Comparable) v1).compareTo(v2);
                        break;
                    } else {
                        throw new IllegalArgumentException("invalid comparison: " + v1.getClass().getName() + " and " + v2.getClass().getName());
                    }
                }
                // else fall through
            case FLOAT:
            case DOUBLE:
                double dv1 = doubleValue(v1),
                dv2 = doubleValue(v2);
                return (dv1 == dv2) ? 0 : ((dv1 < dv2) ? -1 : 1);
            default:
                long lv1 = longValue(v1),
                lv2 = longValue(v2);
                return (lv1 == lv2) ? 0 : ((lv1 < lv2) ? -1 : 1);
            }
        }
        return result;
    }
    /**
     * Returns true if object1 is equal to object2 in either the
     * sense that they are the same object or, if both are non-null
     * if they are equal in the <CODE>equals()</CODE> sense.
     * @param object1 First object to compare
     * @param object2 Second object to compare
     * @return true if object1 == object2
     */
    public static boolean isEqual(Object object1, Object object2) {
        boolean result = false;
        if (object1 == object2) {
            result = true;
        } else {
            if ((object1 != null) && object1.getClass().isArray()) {
                if ((object2 != null) && object2.getClass().isArray() && (object2.getClass() == object1.getClass())) {
                    result = (Array.getLength(object1) == Array.getLength(object2));
                    if (result) {
                        for (int i = 0, icount = Array.getLength(object1); result && (i < icount); i++) {
                            result = isEqual(Array.get(object1, i), Array.get(object2, i));
                        }
                    }
                }
            } else {
                // Check for converted equivalence first, then equals() equivalence
                result = (object1 != null) && (object2 != null) && ((compareWithConversion(object1, object2) == 0) || object1.equals(object2));
            }
        }
        return result;
    }
    /**
     * Evaluates the given object as a boolean: if it is a Boolean object, it's easy; if
     * it's a Number or a Character, returns true for non-zero objects; and otherwise
     * returns true for non-null objects.
     *
     * @param value an object to interpret as a boolean
     * @return the boolean value implied by the given object
     */
    public static boolean booleanValue(Object value) {
        if (value == null)
            return false;
        Class c = value.getClass();
        if (c == Boolean.class)
            return ((Boolean) value).booleanValue();
        //        if ( c == String.class )
        //            return ((String)value).length() > 0;
        if (c == Character.class)
            return ((Character) value).charValue() != 0;
        if (value instanceof Number)
            return ((Number) value).doubleValue() != 0;
        return true; // non-null
    }
    /**
     * Evaluates the given object as a long integer.
     *
     * @param value an object to interpret as a long integer
     * @return the long integer value implied by the given object
     * @throws NumberFormatException if the given object can't be understood as a long integer
     */
    public static long longValue(Object value) throws NumberFormatException {
        if (value == null)
            return 0L;
        Class c = value.getClass();
        if (c.getSuperclass() == Number.class)
            return ((Number) value).longValue();
        if (c == Boolean.class)
            return ((Boolean) value).booleanValue() ? 1 : 0;
        if (c == Character.class)
            return ((Character) value).charValue();
        return Long.parseLong(stringValue(value, true));
    }
    /**
     * Evaluates the given object as a double-precision floating-point number.
     *
     * @param value an object to interpret as a double
     * @return the double value implied by the given object
     * @throws NumberFormatException if the given object can't be understood as a double
     */
    public static double doubleValue(Object value) throws NumberFormatException {
        if (value == null)
            return 0.0;
        Class c = value.getClass();
        if (c.getSuperclass() == Number.class)
            return ((Number) value).doubleValue();
        if (c == Boolean.class)
            return ((Boolean) value).booleanValue() ? 1 : 0;
        if (c == Character.class)
            return ((Character) value).charValue();
        String s = stringValue(value, true);
        return (s.length() == 0) ? 0.0 : Double.parseDouble(s);
        /*
            For 1.1 parseDouble() is not available
         */
        //return Double.valueOf( value.toString() ).doubleValue();
    }
    /**
     * Evaluates the given object as a BigInteger.
     *
     * @param value an object to interpret as a BigInteger
     * @return the BigInteger value implied by the given object
     * @throws NumberFormatException if the given object can't be understood as a BigInteger
     */
    public static BigInteger bigIntValue(Object value) throws NumberFormatException {
        if (value == null)
            return BigInteger.valueOf(0L);
        Class c = value.getClass();
        if (c == BigInteger.class)
            return (BigInteger) value;
        if (c == BigDecimal.class)
            return ((BigDecimal) value).toBigInteger();
        if (c.getSuperclass() == Number.class)
            return BigInteger.valueOf(((Number) value).longValue());
        if (c == Boolean.class)
            return BigInteger.valueOf(((Boolean) value).booleanValue() ? 1 : 0);
        if (c == Character.class)
            return BigInteger.valueOf(((Character) value).charValue());
        return new BigInteger(stringValue(value, true));
    }
    /**
     * Evaluates the given object as a BigDecimal.
     *
     * @param value an object to interpret as a BigDecimal
     * @return the BigDecimal value implied by the given object
     * @throws NumberFormatException if the given object can't be understood as a BigDecimal
     */
    public static BigDecimal bigDecValue(Object value) throws NumberFormatException {
        if (value == null)
            return BigDecimal.valueOf(0L);
        Class c = value.getClass();
        if (c == BigDecimal.class)
            return (BigDecimal) value;
        if (c == BigInteger.class)
            return new BigDecimal((BigInteger) value);
        if (c.getSuperclass() == Number.class)
            return new BigDecimal(((Number) value).doubleValue());
        if (c == Boolean.class)
            return BigDecimal.valueOf(((Boolean) value).booleanValue() ? 1 : 0);
        if (c == Character.class)
            return BigDecimal.valueOf(((Character) value).charValue());
        return new BigDecimal(stringValue(value, true));
    }
    /**
     * Evaluates the given object as a String and trims it if the trim flag is true.
     *
     * @param value an object to interpret as a String
     * @return the String value implied by the given object as returned by the toString() method,
              or "null" if the object is null.
     */
    public static String stringValue(Object value, boolean trim) {
        String result;
        if (value == null) {
            result = OgnlRuntime.NULL_STRING;
        } else {
            result = value.toString();
            if (trim) {
                result = result.trim();
            }
        }
        return result;
    }
    /**
     * Evaluates the given object as a String.
     *
     * @param value an object to interpret as a String
     * @return the String value implied by the given object as returned by the toString() method,
              or "null" if the object is null.
     */
    public static String stringValue(Object value) {
        return stringValue(value, false);
    }
    /**
     * Returns a constant from the NumericTypes interface that represents the numeric
     * type of the given object.
     *
     * @param value an object that needs to be interpreted as a number
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(Object value) {
        int result = NONNUMERIC;
        if (value != null) {
            Class c = value.getClass();
            if (c == Integer.class)
                return INT;
            if (c == Double.class)
                return DOUBLE;
            if (c == Boolean.class)
                return BOOL;
            if (c == Byte.class)
                return BYTE;
            if (c == Character.class)
                return CHAR;
            if (c == Short.class)
                return SHORT;
            if (c == Long.class)
                return LONG;
            if (c == Float.class)
                return FLOAT;
            if (c == BigInteger.class)
                return BIGINT;
            if (c == BigDecimal.class)
                return BIGDEC;
        }
        return NONNUMERIC;
    }
    /**
       * Returns the value converted numerically to the given class type
       *
       * This method also detects when arrays are being converted and
       * converts the components of one array to the type of the other.
       *
       * @param value an object to be converted to the given type
       * @param toType class type to be converted to
       * @return converted value of the type given, or value if the value
       *                cannot be converted to the given type.
     */
    public static Object convertValue(Object value, Class toType) {
        Object result = null;
        if (value != null) {
            /* If array -> array then convert components of array individually */
            if (value.getClass().isArray() && toType.isArray()) {
                Class componentType = toType.getComponentType();
                result = Array.newInstance(componentType, Array.getLength(value));
                for (int i = 0, icount = Array.getLength(value); i < icount; i++) {
                    Array.set(result, i, convertValue(Array.get(value, i), componentType));
                }
            } else {
                if ((toType == Integer.class) || (toType == Integer.TYPE))
                    result = new Integer((int) longValue(value));
                if ((toType == Double.class) || (toType == Double.TYPE))
                    result = new Double(doubleValue(value));
                if ((toType == Boolean.class) || (toType == Boolean.TYPE))
                    result = booleanValue(value) ? Boolean.TRUE : Boolean.FALSE;
                if ((toType == Byte.class) || (toType == Byte.TYPE))
                    result = new Byte((byte) longValue(value));
                if ((toType == Character.class) || (toType == Character.TYPE))
                    result = new Character((char) longValue(value));
                if ((toType == Short.class) || (toType == Short.TYPE))
                    result = new Short((short) longValue(value));
                if ((toType == Long.class) || (toType == Long.TYPE))
                    result = new Long(longValue(value));
                if ((toType == Float.class) || (toType == Float.TYPE))
                    result = new Float(doubleValue(value));
                if (toType == BigInteger.class)
                    result = bigIntValue(value);
                if (toType == BigDecimal.class)
                    result = bigDecValue(value);
                if (toType == String.class)
                    result = stringValue(value);
            }
        } else {
            if (toType.isPrimitive()) {
                result = OgnlRuntime.getPrimitiveDefaultValue(toType);
            }
        }
        return result;
    }
    /**
     * Returns the constant from the NumericTypes interface that best expresses the type
     * of a numeric operation on the two given objects.
     *
     * @param v1 one argument to a numeric operator
     * @param v2 the other argument
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(Object v1, Object v2) {
        return getNumericType(v1, v2, false);
    }
    /**
     * Returns the constant from the NumericTypes interface that best expresses the type
     * of an operation, which can be either numeric or not, on the two given types.
     *
     * @param t1 type of one argument to an operator
     * @param t2 type of the other argument
     * @param canBeNonNumeric whether the operator can be interpreted as non-numeric
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(int t1, int t2, boolean canBeNonNumeric) {
        if (t1 == t2)
            return t1;
        if (canBeNonNumeric && (t1 == NONNUMERIC || t2 == NONNUMERIC || t1 == CHAR || t2 == CHAR))
            return NONNUMERIC;
        if (t1 == NONNUMERIC)
            t1 = DOUBLE; // Try to interpret strings as doubles...
        if (t2 == NONNUMERIC)
            t2 = DOUBLE; // Try to interpret strings as doubles...
        if (t1 >= MIN_REAL_TYPE) {
            if (t2 >= MIN_REAL_TYPE)
                return Math.max(t1, t2);
            if (t2 < INT)
                return t1;
            if (t2 == BIGINT)
                return BIGDEC;
            return Math.max(DOUBLE, t1);
        } else if (t2 >= MIN_REAL_TYPE) {
            if (t1 < INT)
                return t2;
            if (t1 == BIGINT)
                return BIGDEC;
            return Math.max(DOUBLE, t2);
        } else
            return Math.max(t1, t2);
    }
    /**
     * Returns the constant from the NumericTypes interface that best expresses the type
     * of an operation, which can be either numeric or not, on the two given objects.
     *
     * @param v1 one argument to an operator
     * @param v2 the other argument
     * @param canBeNonNumeric whether the operator can be interpreted as non-numeric
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(Object v1, Object v2, boolean canBeNonNumeric) {
        return getNumericType(getNumericType(v1), getNumericType(v2), canBeNonNumeric);
    }
    /**
     * Returns a new Number object of an appropriate type to hold the given integer
     * value.  The type of the returned object is consistent with the given type
     * argument, which is a constant from the NumericTypes interface.
     *
     * @param type    the nominal numeric type of the result, a constant from the NumericTypes interface
     * @param value   the integer value to convert to a Number object
     * @return        a Number object with the given value, of type implied by the type argument
     */
    public static Number newInteger(int type, long value) {
        switch (type) {
        case BOOL:
        case CHAR:
        case INT:
            return new Integer((int) value);
        case FLOAT:
            if ((long) (float) value == value) {
                return new Float((float) value);
            }
            // else fall through:
        case DOUBLE:
            if ((long) (double) value == value) {
                return new Double((double) value);
            }
            // else fall through:
        case LONG:
            return new Long(value);
        case BYTE:
            return new Byte((byte) value);
        case SHORT:
            return new Short((short) value);
        default:
            return BigInteger.valueOf(value);
        }
    }
    /**
     * Returns a new Number object of an appropriate type to hold the given real value.
     * The type of the returned object is always either Float or Double, and is only
     * Float if the given type tag (a constant from the NumericTypes interface) is
     * FLOAT.
     *
     * @param type    the nominal numeric type of the result, a constant from the NumericTypes interface
     * @param value   the real value to convert to a Number object
     * @return        a Number object with the given value, of type implied by the type argument
     */
    public static Number newReal(int type, double value) {
        if (type == FLOAT)
            return new Float((float) value);
        return new Double(value);
    }
    public static Object binaryOr(Object v1, Object v2) {
        int type = getNumericType(v1, v2);
        if (type == BIGINT || type == BIGDEC)
            return bigIntValue(v1).or(bigIntValue(v2));
        return newInteger(type, longValue(v1) | longValue(v2));
    }
    public static Object binaryXor(Object v1, Object v2) {
        int type = getNumericType(v1, v2);
        if (type == BIGINT || type == BIGDEC)
            return bigIntValue(v1).xor(bigIntValue(v2));
        return newInteger(type, longValue(v1) ^ longValue(v2));
    }
    public static Object binaryAnd(Object v1, Object v2) {
        int type = getNumericType(v1, v2);
        if (type == BIGINT || type == BIGDEC)
            return bigIntValue(v1).and(bigIntValue(v2));
        return newInteger(type, longValue(v1) & longValue(v2));
    }
    public static boolean equal(Object v1, Object v2) {
        if (v1 == null)
            return v2 == null;
        if (v1 == v2 || isEqual(v1, v2))
            return true;
        if (v1 instanceof Number && v2 instanceof Number)
            return ((Number) v1).doubleValue() == ((Number) v2).doubleValue();
        return false;
    }
    public static boolean less(Object v1, Object v2) {
        return compareWithConversion(v1, v2) < 0;
    }
    public static boolean greater(Object v1, Object v2) {
        return compareWithConversion(v1, v2) > 0;
    }
    public static boolean in(Object v1, Object v2) throws OgnlException {
        if (v2 == null) // A null collection is always treated as empty
            return false;
        ElementsAccessor elementsAccessor = OgnlRuntime.getElementsAccessor(OgnlRuntime.getTargetClass(v2));
        for (Enumeration e = elementsAccessor.getElements(v2); e.hasMoreElements();) {
            Object o = e.nextElement();
            if (equal(v1, o))
                return true;
        }
        return false;
    }
    public static Object shiftLeft(Object v1, Object v2) {
        int type = getNumericType(v1);
        if (type == BIGINT || type == BIGDEC)
            return bigIntValue(v1).shiftLeft((int) longValue(v2));
        return newInteger(type, longValue(v1) << (int) longValue(v2));
    }
    public static Object shiftRight(Object v1, Object v2) {
        int type = getNumericType(v1);
        if (type == BIGINT || type == BIGDEC)
            return bigIntValue(v1).shiftRight((int) longValue(v2));
        return newInteger(type, longValue(v1) >> (int) longValue(v2));
    }
    public static Object unsignedShiftRight(Object v1, Object v2) {
        int type = getNumericType(v1);
        if (type == BIGINT || type == BIGDEC)
            return bigIntValue(v1).shiftRight((int) longValue(v2));
        if (type <= INT)
            return newInteger(INT, ((int) longValue(v1)) >>> (int) longValue(v2));
        return newInteger(type, longValue(v1) >>> (int) longValue(v2));
    }
    public static Object add(Object v1, Object v2) {
        int type = getNumericType(v1, v2, true);
        switch (type) {
        case BIGINT:
            return bigIntValue(v1).add(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).add(bigDecValue(v2));
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) + doubleValue(v2));
        case NONNUMERIC:
            int t1 = getNumericType(v1),
            t2 = getNumericType(v2);
            if (((t1 != NONNUMERIC) && (v2 == null)) || ((t2 != NONNUMERIC) && (v1 == null))) {
                throw new NullPointerException();
            }
            return stringValue(v1) + stringValue(v2);
        default:
            return newInteger(type, longValue(v1) + longValue(v2));
        }
    }
    public static Object subtract(Object v1, Object v2) {
        int type = getNumericType(v1, v2);
        switch (type) {
        case BIGINT:
            return bigIntValue(v1).subtract(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).subtract(bigDecValue(v2));
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) - doubleValue(v2));
        default:
            return newInteger(type, longValue(v1) - longValue(v2));
        }
    }
    public static Object multiply(Object v1, Object v2) {
        int type = getNumericType(v1, v2);
        switch (type) {
        case BIGINT:
            return bigIntValue(v1).multiply(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).multiply(bigDecValue(v2));
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) * doubleValue(v2));
        default:
            return newInteger(type, longValue(v1) * longValue(v2));
        }
    }
    public static Object divide(Object v1, Object v2) {
        int type = getNumericType(v1, v2);
        switch (type) {
        case BIGINT:
            return bigIntValue(v1).divide(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).divide(bigDecValue(v2), BigDecimal.ROUND_HALF_EVEN);
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) / doubleValue(v2));
        default:
            return newInteger(type, longValue(v1) / longValue(v2));
        }
    }
    public static Object remainder(Object v1, Object v2) {
        int type = getNumericType(v1, v2);
        switch (type) {
        case BIGDEC:
        case BIGINT:
            return bigIntValue(v1).remainder(bigIntValue(v2));
        default:
            return newInteger(type, longValue(v1) % longValue(v2));
        }
    }
    public static Object negate(Object value) {
        int type = getNumericType(value);
        switch (type) {
        case BIGINT:
            return bigIntValue(value).negate();
        case BIGDEC:
            return bigDecValue(value).negate();
        case FLOAT:
        case DOUBLE:
            return newReal(type, -doubleValue(value));
        default:
            return newInteger(type, -longValue(value));
        }
    }
    public static Object bitNegate(Object value) {
        int type = getNumericType(value);
        switch (type) {
        case BIGDEC:
        case BIGINT:
            return bigIntValue(value).not();
        default:
            return newInteger(type, ~longValue(value));
        }
    }
}
